What do we call a public meeting or march that protests against a specific issue?

A public meeting or march that protests against a specific issue is referred to as a demonstration. Demonstrations are organized gatherings where individuals come together to express their opinions, advocate for change, or draw attention to particular causes. They typically involve participants conveying messages through slogans, speeches, and various forms of expressive action, making them a powerful tool for raising awareness and influencing public policy or societal attitudes.

While a rally may have similar characteristics, it typically focuses more on gathering support for a cause rather than protesting against a specific issue. A petition is a written request signed by multiple individuals advocating for a particular action, while a forum usually refers to a space for discussion or debate rather than a direct action like a march or meeting. Thus, "demonstration" captures the essence of this form of protest accurately.